Graces is one I haven't played yet. I've Played about halfway through Symphonia, I wanna say I'm about a third of the way through Xillia, though I'll have to start over since I was playing on my brother's playstation, and I have played up to 3/4ths of Vesperia.
So far all I've done is covered all three system companies, Nintendo, Microsoft and Sony with the Tales of series. XD
Oh if you like Tales of, try Eternal Sonata. That one is about as good as the Tales series.